Richard Eddy, Product Manager, Below Ground Drainage, Polypipe Building Products outlines the impact of the introduction of the new Sewers Code for Adoption from Water UK
In the middle of a national lockdown, and at a time when many building sites and contractors were working significantly reduced hours and remits, the introduction of a new Sewers Code for Adoption from Water UK may have passed under the radar when it came into effect on 1st April.
However, as the industry continues to move back up to full time work, this national guidance on how drainage can be used offers new opportunities for builders already needing to adapt to evolving Building Regulations, the mooted future homes standard and calls across the construction industry to turn the adversity of 2020 into a once-in-a-generation chance for adopting new practices. The good news is, when it comes to the changing definitions and requirements of drainage on developments, the solutions are already there to be found in the marketplace.
The Sewers Code for Adoption guidance includes a Design and Construction Guidance document that affects the adoption of sustainable drainage systems (SuDS) and below ground drainage systems on all development sites in England, providing developers and contractors with an updated, standardised set of delivery procedures.
The main focus of the new guidelines is aimed at increasing the use of hard and soft SuDS at the outset of a development, in response to the rising rainfall in the country, and the recognition that distributing surplus water directly into sewers is unsustainable.
The significant difference from the preceding Sewers for Adoption 7 guidance is that the definition of a sewer is changing from a channel that supplies ‘working outfall’ to one that offers ‘effective outfall’. The upshot is that a lot of SuDS systems, which would not have been considered adoptable under the old regime, can now be classified as such, subject to the correct design and specification being followed.
The framework has been put in place for the use of a greater range of below ground and above ground water drainage systems, from the use of geocellular attenuation systems, such as Polystorm from Polypipe, to soft SuDS systems including natural culverts, water run-off systems and permeable paving, alongside the traditional use of large diameter pipe systems.
In addition, while the former regulations allowed water companies to vary requirements on products and systems deployed for drainage systems, the updated guidance ensures that all products and materials are evaluated by the same standards across England.
Importantly, there is an explicit instruction that the use of plastic-based pipes for below ground drainage can be considered on all sites. This means that there are now regions in England where house builders and developers can choose from a greater range of products and systems to suit their project objectives.
This is where working with a manufacturer can provide rewards. Polypipe has developed and is constantly working to add to what is the UK’s widest and most varied range of plastic-based drainage and water management systems.
In the last 12 months alone Polypipe has introduced the new MCD100 domestic drainage channel range, a sturdy and simple to fit system that works with any surface including block paving, flagstones, tarmac or concrete to assist with the removal of standing water close to a building plot, and the IC600 range of inspection chambers as an adoptable alternative to traditional concrete ring manholes.
An example of how the new Design and Construction Guidance can be applied is found below. The diagram shows the correct installation method in a pedestrian area of the IC600 base, riser, adaptors and cap, with an A15 rated UG510 cover and frame.
The diagram shows the correct installation method in a pedestrian area of the IC600 base, riser, adaptors and cap, with an A15 rated UG510 cover and frame.
Under the new Sewer Code for Adoption, the IC600 bases are suitable for connection to smoothwall underground pipes of 160mm, 250mm, or 315mm diameter, or connected with other Polypipe Polysewer pipes of 150mm, 225mm, and 300mm when installed with the appropriate adaptor systems.
Builders now have more options in front of them to install a suitable drainage system, and are able to draw on a greater range of materials and products to develop solutions that meet the design specification of the developer, water company.
The industry has been calling for a framework that allows for a more holistic approach to water management, and the new Sewers Code for Adoption can pave the way for the design and installation of systems where above ground drainage and below ground drainage solutions can work closer in tandem.
Polypipe is best placed to advise home builders, from large developers to small plot builders on how the new Sewers Code for Adoption will affect their projects, with our below ground drainage technical experts available to offer guidance.
For further information on Polypipe’s range of solutions visit polypipe.com/